This invention relates to a collecting apparatus for scattering toner.
Generally, in a recording apparatus such as an electrophotographic copying machine, an electrostatic recording apparatus or the like, a fine colored powder referred to as toner is widely used as a developing agent to develop an electrostatic latent image. Being a fine powder, this toner is susceptible to scattering in the interior of the recording apparatus, thereby resulting in various problems. In the developing portion of a recording apparatus, the toner must be placed in direct contact with the supporting surface (as of a photosensitive member) on which the latent image of an original document to be copied is formed. As the supporting surface is operatively moved in corresponding relation to scanning of the original document, the scattering of toner brought into contact with the latent image bearing surface inevitably occurs within the machine interior. Yet it is virtually impossible to effectively close the development chamber and, in many cases, an air flow normally circulated within the interior of the recording apparatus for cooling and the like further contributes to toner scattering. As a consequence, the scattering toner contaminates the interior of the apparatus, stains or degrades the visible image formed in the copying process, and additionally hinders effective functioning of the apparatus.
It is therefore desirable to collect such scattering toner and the prior art teaches, for such purpose, forced transport of scattering toner by a stream of air and collection by a filter inserted in the air stream path. In known collecting means of this type, however, clogging of the filter readily occurs due to the fine, powdery nature of the toner and, in operation, such a system has been found to be extremely inefficient as its collection capacity is very small.